1. Field of the Invention
This invention relates to apparatus for obtaining hematocrit readings and more particularly, to a semiautomatic hematocrit reader wherein an operator moves a cursor to identify the pertinent data points on a microhematocrit capillary tube and the device automatically calculates and displays the hematocrit reading.
2. The Prior Art
Blood consists of numerous components but can be roughly classified as including cells in a fluid matrix which is referred to generally as the plasma. The ratio of blood cells to plasma is known as the hematocrit of the blood and is an important parameter for diagnostic and consequent therapeutic purposes. Conventionally, hematocrit of a drop of blood is obtained by drawing the blood by capillary action into a microhematocrit capillary tube. The end of the capillary tube is plugged by being pushed into a putty-like compound such as a clay. The small plug of clay forms a sealing relationship in the end of the capillary tube. Separation of the blood cells from the plasma is achieved under very high centrifugal forces in a high speed centrifuge apparatus where several minutes of high speed centrifugation are required to achieve the desired degree of separation. Uniformity of results is obtained by consistency in the centrifugation processing of the blood sample in each capillary tube.
After centrifugation the capillary tube is compared with a chart that is a graphical representation of various hematocrit readings as a function of total volume of blood in the capillary tube. These charts are usually presented in a scroll-like configuration so as to accommodate the large amount of chart information in a relatively small space. Even a skilled operator must spend considerable time finding the correct total blood volume line and then moving the hematocrit tube to match the blood/plasma interface with the appropriate hematocrit reading line. Thereafter the operator determines the correct chart line and transcribe this reading to the appropriate medical chart or document.
From the foregoing it is readily apparent that valuable time is consumed and many opportunities for error occur not only in the matching of the capillary tube to the chart but also in the interpolation of the chart and in transcribing the information. Clearly, any significant error could prove catastrophic to a patient if the wrong therapeutic procedures were prescribed as a result of an erroneous hematocrit reading. In view of the foregoing, it would be an advancement in the art to provide a semiautomatic hematocrit reader apparatus whereby the operator simply moves a cursor to the various data entry points and the apparatus automatically calculates the hematocrit reading. Such a novel apparatus and method is disclosed and claimed herein.